This invention relates to a process and apparatus for performing chemical reactions, e.g., methanation of carbon oxides with hydrogen, in a reactor containing a bed of catalyst, especially particulate solid catalyst, said reactor being further provided with indirect heat exchange means. The invention is particularly applicable to exothermic catalytic reactions, with the indirect heat exchange means being used for cooling the catalyst bed.
A reactor that can be used for performing such a process is described in DOS No. 2,848,014. In this reactor, two tube bundle heat exchangers are arranged in axially offset relationship within a catalyst bed; these heat exchangers can be charged with coolant independently of each other whereby different temperatures can be selected over the length of the catalyst bed. As an additional feature of this reactor, feed pipes for the reaction mixture are provided within the catalyst bed. This process involves a so-called cold-gas quench feed which constitutes additional cooling means for avoiding excessively high peak temperatures in the catalyst bed. The conventional reactor thus comprises three, more or less independently controllable cooling systems which, though ensuring a high degree of flexibility of temperature control, is very expensive to construct on the one hand and to equip with associated temperature control means on the other hand.